We will characterize the folded DNA structures from interphase nuclei of Physarum polycephalum plasmodia and from a cell line of Drosophila Melanogaster. The folded DNA will be analyzed by sedimentation and viscometry, and the macromolecules (RNA, proteins) present in the complex will be identified. Folded DNA will also be isolated from nuclei in mitosis, to determine whether a similar pattern of DNA folding can be found after gentle extraction of the metaphase chromosomes. We will study the nature of protein-DNA and RNA-DNA interactions which results in the long range crosslinking and folding of the DNA in eucaryotic nuclei.